*{
  margin: 0;
  padding: 0;
}
body{
  background-color: rgb(241, 242, 246);
}
//设置浮动
.fl{
  float: left;
}
.fr{ // 右浮动
  float: right;
}
//清除浮动
.clear:after{
  content:"";
  height: 0;
  display: block;
  clear: both;
}
.mt{
  margin-top: 20px;
}
.mb {
  margin-bottom: 20px;
}
.ml {
  margin-left: 20px;
}
.mr {
  margin-right: 20px;
}
// 隐藏滚动条
::-webkit-scrollbar{
  display: none;
}